Unveiling giant hidden Rashba effects in two-dimensional Si2Bi2

Abstract

Recently, it has been known that the hidden Rashba (R-2) effect in two-dimensional materials gives rise to a physical phenomenon called spin-layer locking (SLL). However, not only its underlying fundamental mechanism has been unclear, but also there are only a few materials exhibiting weak SLL. Here, through the first-principles density functional theory and model Hamiltonian calculation, we reveal that the R-2 SLL can be determined by the competition between the sublayer–sublayer interaction and the spin–orbit coupling, which is related to the Rashba strength. In addition, the orbital angular momentum distribution is another crucial point to realize the strong R-2 SLL. We propose that a 2D material Si2Bi2 possesses an ideal condition for the strong R-2 SLL, whose Rashba strength is evaluated to be 2.16 eVÅ, which is the greatest value ever observed in 2D R-2 materials to the best of our knowledge. Furthermore, we reveal that the interlayer interaction in a bilayer structure ensures R-2 states spatially farther apart, implying a potential application in spintronics.

Hidden interplay of current-induced spin and orbital torques in bulk Fe$_3$GeTe$_2$

“…Thus, individual layers host local torques in a "staggered" manner although the total torque vanishes. We note that a similar situation is encountered in other centrosymmetric systems, for which the concept of the "hidden" Rashba effect has been de-veloped [16][17][18].…”

Spin–orbit splitting and piezoelectric properties of Janus Ge2XY (X ≠ Y = P, As, Sb and Bi)

“…61 In addition, the increase in the dipole moment m depends on the increase in the work function difference, which is consistent with the Helmholtz equation. 64…”

Novel Polytype of III–VI Metal Chalcogenides Nano Crystals Realized in Epitaxially Grown InTe

“…Indeed, because of the high atomic number in families III–VI on the periodic table and its strong spin‐orbit coupling, vdW InTe may exhibit exotic physical properties, such as unconventional hidden Rashba effects and inverted band structures. [ 26 ] Moreover, vdW layered InTe has the smallest bandgap among layered III–VI family members, making it ideal for applications requiring an optical response in the infrared range. [ 19–21 ] Thus, there is a need to synthesize InTe and investigate its layered structure and stacking order to expand current knowledge regarding the III–VI family.…”